This invention relates to novel hair fixing compositions which exhibit superior hydrocarbon tolerance and are suitable for use in aerosol applications wherein hydrocarbon propellants are used.
In order to be effective in aerosol hair spray formulations, the film forming, polymeric binders utilized therein as well as the films derived therefrom must meet a rigid set of requirements. The binders used in such formulations should be soluble in organic solvents; yet the films cast from such hair spray formulations should, ordinarily, be either water soluble or water dispersible in order to facilitate their easy removal from the user's hair. As is readily visualized, this is an unusual combination of properties which is further complicated by the requirement that the binder used in such formulations be completely compatible with the propellants and solvents ordinarily employed therein. Further, the binders should be stable in the presence of, and unreactive with, the perfumes or other optional ingredients utilized in hair spray formulations.
In addition, the films cast from either aqueous or organic solvent solutions of these binders should be flexible and yet they should have sufficient strength and elasticity; they should adhere well to hair so as to avoid dusting or flaking off when the hair is subjected to varying stresses; they should readily allow the hair to be recombed; they should maintain a nontacky state despite varying environmental conditions; they should be clear, transparent and glossy and should maintain this clarity on aging; they should possess good anti-static properties; and, they should be easily removable by the use of water and/or soap or shampoo.
Many polymeric systems have been utilized in an attempt to meet these stringent requirements. Among these are included; polyvinylpyrrolidone, copolymers of N-vinyl pyrrolidone with vinylacetate, 5-5'-dimethyl hydantoinformaldehyde resins and copolymers of methyl vinyl ethers and maleic acid half esters, etc. Though each of the latter systems has met at least some o the above cited requirements, none has exhibited all of these requirements to an optimum degree.
For example, carboxylated vinyl polymeric hair spray resins, particularly the carboxylated acrylate, and/or acetate based resins, have long been favored for use in aerosol hair spray formulations. Also useful are a class of carboxylated ester polymers comprising an acrylamide, an acidic film forming comonomer, and at least one polymerizable comonomer which are described in U.S. Pat. No. 3,927,199. In order to obtain optimum benefits for the use of such acidic resins, it has been required to neutralize at least a portion, and preferably all, of the available carboxyl functionalities with specific alkaline reagents, e.g. amines and aminohydroxy compounds, as described in, for example, U.S. Pat. Nos. 2,996,471; 3,405,084; 3,577,517, etc. Thus, alkaline reagents which are suggested for such neutralizations include ammonia, lithium hydroxide, potassium hydroxide, sodium hydroxide, mono-, di- or tri-ethanolamine, mono-, di or tripropanolamine, morpholine, amino ethyl ethanol amine, amino metyl propanol, amino methyl propanediol, hydroxy ethyl morpholine, and mixtures thereof. The purpose of this neutralization step is both to improve the water solubility or dispersibility of the resin thus permitting easy removal from the hair by merely washing with shampoo and also to affect the degree of flexibility of the resultant film when sprayed on the hair (i.e. to produce a soft film, normal film or a film suitable for "hard to hold" hair). Additionally, U.S. Pat. No. 4,192,861 teaches the use of long chain amines for the neutralization of specific polymers in aerosol hairspray systems.
Recent ecological considerations have resulted in a shift away from the use of certain halogenated propellants and cosolvents and toward the use of hydrocarbons as propellants in aerosol hair spray formulations. In such systems, the binder and any optional ingredients are dissolved in a suitable solvent, such as an alcohol, and the hydrocarbon serves as the propellant. Unfortunately, the use of these propellants produces a number of problems, some of which are due to the decrease in solubility of the binder in the alcohol as the hydrocarbon content is increased to a level acceptable for use as a propellant. Thus, while the carboxylated resin are soluble in the anhydrous alcohol-halocarbon systems of the prior art, and are the commercially preferred resins for their hair holding properties, their reduced solubility in the alcohol-hydrocarbon propellant may render them unacceptable to the industry for use in aerosol systems containing high levels of hydrocarbon propellants.
Thus, there exists a need for hairspray formulations which exhibit desirable hair fixing properties as well as high tolerance of hydrocarbon propellants which are becoming increasingly important in the industry.